Electromagnetic relay



Oct. 18, 1927.

CROWE I ELECTROMAGNETIC RELAY Filed Feb. 5, 1925 Patented Oct. 18, 1927.

UNITED STATES Application filed February 5, 1923, Serial No.

This invention relates to electro-magnetic relays and is particularly designed for use in telephone and signalling systems or in other situations where it may be required to actuate any one contact or element or any one set of contacts or other elements of a group comprising a number of such elements or sets of elements.

Usually the selection of any particular element or set of elements is effected by providing a relay for each of such elements or sets of elements and it is the object of the present invention to devise means whereby the required conditions may be obtained without the use of a number of independent relays with independent circuits and actuating means therefor, thus resulting in the cheapening of the cost and a simplification of manufactureand a decrease in maintenance charges.

The invention consists in a multiple electro-magnetic relay comprising a plurality of relay armatures actuated electro -magnetically and means whereby any particular armature may be operated or selected for operation without afiecting any of the other relay armatures.

The invention also consists in other details and arrangements hereinafter described or indicated.

The accompanying drawings illustrate one form of apparatus in accordance. with the invention.

Figure 1 is a perspective view.

Figure 2 is a transverse sectional elevation.

EigureB is a diagram of connections, and

Figure 4 is a diagrammatic representation of the relay. M

In carrying my invention into efi'ect 'in one convenient manner,- I form my improved multiple relay with the magnetic circuit composed of a yoke piece a secured to a core or bobbin comprising the units 6, c (for example, by being bolted thereto by means of end flanges on the yoke or by other suitable means) of a length determined by the number of relay armatures required to be embodied in the multiple relay. The core or bobbin is formed along its length or is provided thereon with a number of flanges or rings d, the number of which is equal to the number of contacts or elements or setsof such elements requiringto be operated. j I

Each part of the bobbin intermediate of PATENT, OFFICE.

DOUGLAS coRMAoK 'cno'wn, or LONDON, ENGLAND.

I ELECTROMAGNETIC RELAY.

617,165, and in Great Britain March 16, 1922.

the flanges or rings is wound in the samemanner with an insulated wire coil 6 so that 1n this way I form a number of electroe magnetic coils with the leading-out Wire of one coil connected to the leading-in wire of the next and so on throughout the length of the bobbin, while the leading-out .wire of the last coil is connected to the leadingin wire of the first coil, the various joints between the coils being available in any suitable manner for external connection by means of contacts m. The arrangement of the coils is clearly seen in the diagram in Flgure 3. The end bobbins e are arranged at right angles to the bobbin 6 in order to reduce the length of the relay; Pivoted to or otherwise suspended from the yoke a are armatures f which maybe of the usual relay pattern and which are arranged so that each armature is opposite to its respective flange or ring d upon the bobbin with the usual air gap between, and the contacts 9 to be actuated by the relay are so arranged that any particular armature will actuate its appropriate set of contacts, leaving the others unaffected. If now one pole of the battery it be connected to the junction between the end wires and suitable means are provided by which the otherpole of the battery may be connected by means of contacts n to any particular one ofthe intermediate joints m the armature corresponding to such joint will alonerbe actuated while the others will. remain unaffected. This is due to the fact that the current flowing from such junction m in opposite directions towards the outer ends of the coil will set up two opposite magnetic circuits which will meet at the flange or ring corresponding to the particular junction selected, thereby forming one magnetic pole at such flange or ring, while the other pole will beformed somewhere in the yoke, but as the yoke is of ample dimensions and is not electromagnetically controlled along its length. such pole is free to form opposite gap just opposite to the flange dwhere the magnetic pole has been formed is much greater than at the other air gaps which latter will be passed only by a rather weak stray field. It will therefore be possible to adapt the strength of the springs 0 actuating the armature-s 7 so as to cause only the armature corresponding to the flange at selected to be attracted. In this way it will be seen that any particular armature in my improved multiple relay may be readily selected for operation without in any way affecting the other-s notwithstanding that there is a single magnetic circuit and a single actuating battery provided in connection with the whole group of relay armatures. The selecting of the particular pair of contacts m, n to be operated may be efiected in any known manner either manually by means of keys or automatically by means of a selective switch. In Fig. 3 each pair of contacts m, it may for instance be supposed to be operated by a key or push-button. The relay may thus be operated at a distance over the circuits shown in Fig. 3, to

select other circuits controlled by the contact springs g.

' Another reason why the consequent polarity is strongest at the pointin the magnetic circuit where connection is made to junction of coils is as follows: The number or ampere turns on each side of the magnetic circuit, to the left and to the right of the actuated armature remains substantially constant for a given electromotive force impressed on the coils because of the pa-rallel'circuit arrange ment. Suppose for instance, that the armatureat the far right-hand side is to be actuated. When contact is made at the coil opposite this armature a parallel circuit is closed having one coil in the right hand branch and eight, coils in the left hand branch. As the same electromotive force is impressed on each side of this circuit, and one coil has one eighth the resistance of eight coils, eight timesas mucl icurrent will flow through the one coil on the right hand than flows through the eight coils on the left branch. However, as the magneto-motive force is equal to the product of current and coil turns or ampere turns, the magnetomotive force on both sides of the parallel magnetic circuit will be practically equal, resulting in strong polarity at the junction. The same result will be found whichever ar- -mature is actuated.

For the purpose of increasing the usefulness of the relay I may provide means whereby each armature may actuate more than one set of contacts. For'example, I

provide a fixed bar a" through which pass a number of pins is, the upper ends of which ,fit loosely in holes in a movable bar Z adapted to be actuated by an electro-magnet p the circuit of which may be controlled at a distance. Thus the pins may be rocked so that their upper ends register with one or other of two or more sets of contacts, and then each armature may control such sets of contacts.

It will be understood that the invention is not to be limited to theforegoing details of construction which are given by way of illustration only, as it will be clear tha-t1 may modify the number and mode of ar rangement of the armatures, the means whereby such armatures may be adapted to actuate the contacts or other elements which they are to control and the form and arrangement of magnetic circuit adopted to suit the particular purpose for which the electro-magnetic relay is to be employed or any particular practical requirements tha may have to be fulfilled.

Claims: 1. A multiple electro-magnetic relay comprising a single magnetic circuit, a plurality of electro-magnetically actuated relay armatures associated therewith, a number of magnetizingwindings and means for changing the path of the magnetic flux for selectively operating any one of the armat-ures, without affecting the other armatures.

2. A multiple electro-magnetic relay comprising a single magneticcircuit, a plurality of electro-magnet-ically operated armatures associated therewith, magnetically interconnected pole pieces arranged one opposite to each armature, a number of magnetizing windings and means for directing the magnetic flux through any oneof said pole pieces, for operating the correspondingarrings on the bobbin of such coils, a plurality of armatures registering with said rings,

and means whereby a battery may be connected between the jointof the end wires of the coils and the joint between the wires of any two adjacent coils, substantially as' described.

5. A multiple electro-magnetic relay comprising a single magnetic circuit, a vplurality of electro-magnetically actuated relay armatures therefor, means whereby any particular armature may be operated without affectingany of the other armatures, a plurality of contacts in association with each armature, a distance piece between each armature and its contacts and means for moving said distance piece pivotally about the en abutting on to the armature so that each armature may actuate one or other of the contacts as required.

6. A multiple electro-magnetic relay comprising a plurality of coils separated by rings on the bobbin of such coils, a plurality of armatures registering with sald rings,

means whereby a battery may be connected between the joint of the end wires of the coils and joint between the wires of any two adjacent coils, a plurality of contacts associated with each armature, and means whereby each armature may actuate one or other of its plurality of contacts, substantially as described.

In testimony whereof I have signed my 90 name to this specification.

DOUGLAS CORMAGK CROWE. 

